1. Field of the Invention
The present invention relates to a cutting machine comprising:
a chassis connected to a motor vehicle;
a cutting device comprising cutting members and intended to occupy:
at least one work position in which it rests at least approximately on the ground and in which it is intended to follow the relief of said ground,
at least one transport position in which it extends above the ground,
a connecting device connecting the cutting device to the chassis in such a way as to allow said cutting device to be brought into the work position and into the transport position and comprising at least two connecting rods each one connected to said cutting device and to said chassis by means of a respective connection, one of said connections being a connection of the ball-joint type.
2. Discussion of the Background
A cutting machine of this kind is known from most cutting machines and more specifically from most mowers of the trailed type. Broadly speaking, these known mowers comprise a chassis with wheels intended to be connected to a motor vehicle by means of a drawbar. A cutting device is connected to the chassis by means of a connecting device containing lower connecting rods. Each lower connecting rod is connected, on one hand, to the cutting device by means of a connection of the ball-joint type and, on another hand, to the chassis by means of a connection which is also of the ball-joint type. The connecting rods and the ball-joint connections advantageously allow the cutting device to move relative to the chassis in the work position so as to allow said cutting device to follow the relief of the land. Each ball-joint connection comprises a spherical part guided in a concave part and a lubricating device intended to allow a lubricating film to be introduced between said spherical part and said concave part. To ensure that the cutting device works correctly and to lighten it, it is necessary for the ball joints to be lubricated regularly. The fact that these ball joints are frequently exposed to dust or moisture and thrown-up soil makes it all the more important that they be lubricated.
Each connection also comprises a spindle which passes through the corresponding spherical part and which, by means of an operating device, allows the cutting device to be brought from a work position, in which it rests on the ground, into a transport position in which it extends above said ground, or vice versa.
The devices for lubricating these connections are relatively difficult to access, which means that their lubrication is fairly often neglected.
Such connections of the ball-joint type have to experience a minimum amount of movement to prevent them from seizing up when they have been immobile for too long: the start of the cutting season often witnesses mower cutting devices which are very difficult to manipulate from a transport position into a work position or vice versa and which no longer correctly follow the relief of the land.
The object of the present invention is to overcome the drawbacks of the cutting machines of the prior art while at the same time seeking to obtain a simple and inexpensive solution.
To this end, the cutting machine according to the invention is characterized in that at least one of the connections connecting a connecting rod to the cutting device or to the chassis comprises an elastic element.
The invention also relates to the following features taken in isolation or in any technically feasible combination:
the elastic element is made of a natural or synthetic elastomer;
the connection which comprises an elastic element also comprises a ring to the outside of which the elastic element is fixed and through which a spindle extends;
the elastic element is fixed to the ring by vulcanizing;
the ring is made of plastic and the corresponding spindle is made of a rustless material or is surface-coated with a rustless material which advantageously allows the connection always to operate correctly and allows the cutting device to be placed in the work or transport position;
the connecting rod comprises a bore of biconical shape, inside which the corresponding elastic element extends;
on its exterior periphery, the elastic element is of biconical shape, approximately complementing the biconical shape of the corresponding bore in the connecting rod, which advantageously allows the said elastic element to be held firmly in the corresponding bore in said connecting rod;
the bore made in the connecting rod is forged or cast in, which advantageously allows the cost price to be limited;
the cutting device comprises a first lower lateral end, to the vicinity of which a first lower connecting rod is connected by means of a first connection, and a second lower lateral end, to the vicinity of which a second lower connecting rod is connected by means of a second connection;
the chassis comprises a first lower lateral end, to the vicinity of which the first lower connecting rod is connected by means of a third connection, and a second lower lateral end to the vicinity of which the second lower connecting rod is connected by means of a fourth connection;
at least the two connections connecting the two lower connecting rods to the cutting device each comprise an elastic member;
at least the two connections connecting the lower connecting rods to the chassis each comprise an elastic member;
there is a stabilizing device which at least substantially prevents the cutting device from moving transversely to the direction of forward travel;
the stabilizing device consists of one of the lower connecting rods of which the connection connecting it to the cutting device or to the chassis comprises a second elastic element so that the two elastic elements form a connection of the pivot type.